"There is definitely a connection with violence against people," said Lungaro, a former lieutenant in the NYPD's Organized Crime Control Bureau.

The cats were found April 24 in a wooded area in Yonkers.

Necropsies on three of the cats showed their heads were crushed with blunt objects. The bodies of the other animals were so decomposed necropsies have not been performed on them. The killings were not believed to have been ritualistic.

Lungaro, who has been canvassing the neighborhood where the dead cats were found, said Friday there were no suspects yet.

Geberth told The Journal News there was a "psychological and sexual manifestation" to serial killers who had animal cruelty in their backgrounds.

Male serial killers who commit acts of animal cruelty often have "females in their minds," Geberth said.

"Some people don't go beyond this," said Geberth, the author of four books on homicide investigation. "Some people do.

"If I was in law enforcement I would definitely be concerned," Geberth concluded.

Lungaro, 46, called the Yonkers case the toughest one he'd handled in his three years with the SPCA.

"It is definitely unusual," Lungaro said. "They way they were displayed. I have never seen anything like this and neither has anyone else here." Still, he was optimistic he would be able to make an arrest.

Lungaro, who operates full-time with peace officer status, has one part-time officer to help him. Together they handle 2,000 calls yearly on animal cruelty in Westchester County for the SPCA, which is privately funded from donations.

His investigation is being supplemented by detectives from the Yonkers police Detective Division Major Case Unit.

"We are looking at people in and out of the neighborhood," said Yonkers Detective Lt. Patrick McCormack.